Risk Factor For Postoperative Cognitive Dysfunction Research Articles

Dysregulation of the Gut Microbiota Contributes to Sevoflurane-Induced Cognitive Dysfunction in Aged Mice by Activating the NLRP3 Inflammasome.

Postoperative cognitive dysfunction (POCD), a common complication in elderly patients after surgery, seriously affects patients' quality of life. Long-term or repeated inhalation of sevoflurane can cause neuroinflammation, which is a risk factor for POCD. However, the underlying mechanism needs to be further explored. Recent research had revealed a correlation between neurological disorders and changes in the gut microbiota. Dysfunction of the gut microbiota is involved in the occurrence and development of central nervous system diseases. Here, we found that cognitive dysfunction in aged mice induced by sevoflurane exposure (3%, 2 hours daily, for 3 days) was related to gut microbiota dysbiosis, while probiotics improved cognitive function by alleviating dysbiosis. Sevoflurane caused a significant decrease in the abundance of Akkermansia (P<0.05), while probiotics restored the abundance of Akkermansia. Compared to those in the control group, sevoflurane significantly increased the expression of NLRP3 inflammasome-associated proteins in the gut and brain in the sevoflurane-exposed group, thus causing neuroinflammation and synaptic damage, which probiotics can mitigate (con vs. sev, P < 0.01; p+sev vs. sev, P < 0.05). In conclusion, for the first time, our study revealed that dysbiosis of the gut microbiota caused by sevoflurane anesthesia contributes to the NLRP3 inflammasome-mediated neuroinflammation and cognitive dysfunction from the perspective of the gut-brain axis. Perhaps postoperative cognitive impairment in elderly patients can be alleviated or even prevented by regulating the gut microbiota. This study provides new insights and methods for the prevention and treatment of cognitive impairment induced by sevoflurane.

Preoperative mild cognitive impairment as a risk factor of postoperative cognitive dysfunction in elderly patients undergoing spine surgery.

Any persistent degree of cognitive impairment in older adults is a concern as it can progress to dementia. This study aimed to determine the incidence and risk factors for early postoperative cognitive dysfunction (POCD) in elderly patients undergoing spine surgery. Patients were enrolled from a previous prospective observational study after screening for normal cognitive function using the Mini Mental State Examination (MMSE). Cognitive function was evaluated before surgery and at 1 week, month, and year post-surgery using MMSE and Montreal Cognitive Assessment scores (MoCA). Mild cognitive impairment (MCI) was determined using the MoCA scores adjusted for age. POCD was defined as a drop of three or more points on the MMSE 1 week post-surgery. Multivariate logistic analysis was performed to identify POCD risk factors. A total of 427 patients were included. Eighty-five (20%) had pre-existing MCI. The MCI group showed lower MoCA scores at each time point (baseline, 1 week after surgery, 1 month after surgery, 1 year after surgery) compared to the non-MCI group. Those in the MCI group had a higher rate of admission to intensive care unit after surgery, postoperative delirium, and POCD 1 week post-surgery, than those in the non-MCI group (16.5% vs. 6.7%, p = 0.008; 27.1% vs. 15.8%, p = 0.024; and 18.8% vs. 8.2%, p < 0.001, respectively). Among them, 10.3% were assessed for POCD on postoperative day 7 and self-reported poor social roles and physical functioning 1 week postoperatively. Preoperative MCI was seen in ~20% of surgical patients aged >70 years. POCD was seen in ~20% of patients with pre-existing MCI, and ~ 10% of those without. Benzodiazepine use, significant comorbidities, pre-existing MCI, and depressive tendencies were risk factors for POCD.

Post-operative cognitive dysfunction is exacerbated by high-fat diet via TLR4 and prevented by dietary DHA supplementation

Post-operative cognitive dysfunction (POCD) is an abrupt decline in neurocognitive function arising shortly after surgery and persisting for weeks to months, increasing the risk of dementia diagnosis. Advanced age, obesity, and comorbidities linked to high-fat diet (HFD) consumption such as diabetes and hypertension have been identified as risk factors for POCD, although underlying mechanisms remain unclear. We have previously shown that surgery alone, or 3-days of HFD can each evoke sufficient neuroinflammation to cause memory deficits in aged, but not young rats. The aim of the present study was to determine if HFD consumption before surgery would potentiate and prolong the subsequent neuroinflammatory response and memory deficits, and if so, to determine the extent to which these effects depend on activation of the innate immune receptor TLR4, which both insults are known to stimulate. Young-adult (3mo) & aged (24mo) male F344xBN F1 rats were fed standard chow or HFD for 3-days immediately before sham surgery or laparotomy. In aged rats, the combination of HFD and surgery caused persistent deficits in contextual memory and cued-fear memory, though it was determined that HFD alone was sufficient to cause the long-lasting cued-fear memory deficits. In young adult rats, HFD + surgery caused only cued-fear memory deficits. Elevated proinflammatory gene expression in the hippocampus of both young and aged rats that received HFD + surgery persisted for at least 3-weeks after surgery. In a separate experiment, rats were administered the TLR4-specific antagonist, LPS-RS, immediately before HFD onset, which ameliorated the HFD + surgery-associated neuroinflammation and memory deficits. Similarly, dietary DHA supplementation for 4 weeks prior to HFD onset blunted the neuroinflammatory response to surgery and prevented development of persistent memory deficits. These results suggest that HFD 1) increases risk of persistent POCD-associated memory impairments following surgery in male rats in 2) a TLR4-dependent manner, which 3) can be targeted by DHA supplementation to mitigate development of persistent POCD.

Prevalence and characteristics of Postoperative Cognitive Dysfunction (POCD) in on-pump cardiac surgery patients at Dr. Kariadi General Hospital Semarang

Background: Postoperative Cognitive Dysfunction or POCD is a reversible decline in the cognitive function of patients after surgery. The risk factors for POCD are age, comorbidities, duration of CPB, intraoperative hypoperfusion, duration of ventilator use, and postoperative sedation are risk factors of POCD. This study aims to determine the prevalence and characteristics of postoperative cognitive dysfunction (POCD) in patients who undergo on-pump cardiac surgery at Dr. Kariadi General Hospital. Methods: This study's population was all patients undergoing on-pump cardiac surgery at Dr. RSUP. Kariadi in July 2021-December 2021. The study subject was 97 patients, obtained by total sampling technique. The study subjects were examined for cognitive function with MoCA-INA one day before surgery and the third day after surgery. Data were analyzed using SPSS version 23 for Windows. Results: There were 68 (70.1%) patients who experienced POCD and 29 (29.9%) patients who did not experience POCD. The median age of patients with POCD is 50 (18-68) years and 36 (18-63) years for patients without POCD. Based on MAP during CPB, patients with POCD had a median of 64 (51-80) minutes. In patients with POCD, the median length of CPB was 53 (22-92) minutes, and the median length of the aortic cross-clamp clamp was 35 (11-69) minutes. Conclusion: We found a high prevalence of POCD patients after on-pump cardiac surgery, as many as 70.1% at Dr. Kariadi General Hospital.

The Management of Postoperative Cognitive Dysfunction in Cirrhotic Patients: An Overview of the Literature

Background and objectives: Postoperative cognitive dysfunction (POCD) represents a decreased cognitive performance in patients undergoing general anesthesia for major surgery. Since liver cirrhosis is associated with high mortality and morbidity rates, cirrhotic patients also assemble many risk factors for POCD. Therefore, preserving cognition after major surgery is a priority, especially in this group of patients. The purpose of this review is to summarize the current knowledge regarding the effectiveness of perioperative therapeutic strategies in terms of cognitive dysfunction reduction. Data Collection: Using medical search engines such as PubMed, Google Scholar, and Cochrane library, we analyzed articles on topics such as: POCD, perioperative management in patients with cirrhosis, hepatic encephalopathy, general anesthesia in patients with liver cirrhosis, depth of anesthesia, virtual reality in perioperative settings. We included 115 relevant original articles, reviews and meta-analyses, and other article types such as case reports, guidelines, editorials, and medical books. Results: According to the reviewed literature, the predictive capacity of the common clinical tools used to quantify cognitive dysfunction in cirrhotic settings is reduced in perioperative settings; however, novel neuropsychological tools could manage to better identify the subclinical forms of perioperative cognitive impairments in cirrhotic patients. Moreover, patients with preoperative hepatic encephalopathy could benefit from specific preventive strategies aimed to reduce the risk of further neurocognitive deterioration. Intraoperatively, the adequate monitoring of the anesthesia depth, appropriate anesthetics use, and an opioid-sparing technique have shown favorable results in terms of POCD. Early recovery after surgery (ERAS) protocols should be implemented in the postoperative setting. Other pharmacological strategies provided conflicting results in reducing POCD in cirrhotic patients. Conclusions: The perioperative management of the cognitive function of cirrhotic patients is challenging for anesthesia providers, with specific and targeted therapies for POCD still sparse. Therefore, the implementation of preventive strategies appears to remain the optimal attitude. Further research is needed for a better understanding of POCD, especially in cirrhotic patients.

Post-Coronary Artery Bypass Grafting Cognitive Decline: Risk Modification And Implications For Screening In Low-Risk Population

Background — Postoperative cognitive dysfunction (POCD) is an important complication of coronary artery bypass grafting (CABG). Large amount of data points to the problem of POCD in patients with high surgical risk of CABG. Low-risk patients are not safe from these complications either. Assessment of the severity, duration of POCD, degree of recovery and risk factors in off- and on-pump patients with stable coronary artery disease is crucial in minimization of the POCD risk in patients with low surgical risk. Objective — to analyze incidence, severity, reversibility and risk factors of POCD in patients undergoing elective low-risk CABG. Methods and Results — The retrospective cohort study included 79 patients who underwent on-pump (N=44) or off-pump (N=35) elective CABG with low surgical risk (mean EuroSCORE II death risk 1.08±0.71%), with observation period of 6 months. Pre-CABG markers of cognitive impairment were found in 50% of patients, with 44% of patients demonstrating POCD. Patients who underwent off-pump CABG demonstrated more pronounced decline in MoCA score compared to on-pump (-3.9±2.0 vs. -2.2±2.0 at 8 days point, p=0.018), with regress to pre-CABG results after 3 weeks. Baseline MoCA score &lt;25 was found to be a predictor for more pronounced cognitive decline at 8 days point. MMSE demonstrated less predictive value compared to MoCA. Conclusion — POCD risk differs in off-pump and on-pump CABG cohorts, with significantly higher prevalence in the former group, whether assessed using MMSE or MoCA tests. Differences are observed within 3 weeks post-CABG. Pre-CABG MoCA score &lt;25 is associated with more pronounced POCD in low-risk elective CABG cohort.

Appropriate exercise level attenuates gut dysbiosis and valeric acid increase to improve neuroplasticity and cognitive function after surgery in mice

Postoperative cognitive dysfunction (POCD) affects the outcome of millions of patients each year. Aging is a risk factor for POCD. Here, we showed that surgery induced learning and memory dysfunction in adult mice. Transplantation of feces from surgery mice but not from control mice led to learning and memory impairment in non-surgery mice. Low intensity exercise improved learning and memory in surgery mice. Exercise attenuated surgery-induced neuroinflammation and decrease of gut microbiota diversity. These exercise effects were present in non-exercise mice receiving feces from exercise mice. Exercise reduced valeric acid, a gut microbiota product, in the blood. Valeric acid worsened neuroinflammation, learning and memory in exercise mice with surgery. The downstream effects of exercise included attenuating growth factor decrease, maintaining astrocytes in the A2 phenotypical form possibly via decreasing C3 signaling and improving neuroplasticity. Similar to these results from adult mice, exercise attenuated learning and memory impairment in old mice with surgery. Old mice receiving feces from old exercise mice had better learning and memory than those receiving control old mouse feces. Surgery increased blood valeric acid. Valeric acid blocked exercise effects on learning and memory in old surgery mice. Exercise stabilized gut microbiota, reduced neuroinflammation, attenuated growth factor decrease and preserved neuroplasticity in old mice with surgery. These results provide direct evidence that gut microbiota alteration contributes to POCD development. Valeric acid is a mediator for this effect and a potential target for brain health. Low intensity exercise stabilizes gut microbiota in the presence of insult, such as surgery.

Risk factors and predictive value of perioperative neurocognitive disorders in elderly patients with gastrointestinal tumors

BackgroundThis study aims to investigate the risk factors of perioperative neurocognitive disorders (PNDs) mainly including postoperative cognitive dysfunction (POCD) in elderly patients with gastrointestinal tumors, and evaluate its predictive value.MethodsA total of 222 eligible elderly patients (≥65 years) scheduled for elective gastroenterectomy under general anesthesia were enrolled. The cognitive function assessment was carried out 1 day before surgery and 7 days after surgery. Receiver operating characteristic curve analysis was performed to evaluate the predictive value of risk factors for early POCD. The risk factors for POCD were analyzed using univariate and multivariate logistic regression model.ResultsOf all the 222 enrolled patients, 91 (41.0%) developed early POCD and 40 (18.0%) were identified as major POCD within 7 days after the surgery. Visual analogue score (VAS, 1st day, resting) ≥4 (OR = 7.618[3.231–17.962], P < 0.001) and alcohol exposure (OR = 2.398[1.174–4.900], P = 0.016) were independent risk factors for early POCD. VAS score (1st, resting) ≥4 (OR = 13.823[4.779–39.981], P < 0.001), preoperative white blood cell (WBC) levels ≥10 × 10*9/L (OR = 5.548[1.128–26.221], P = 0.035), blood loss ≥500 ml (OR = 3.317[1.094–10.059], P = 0.034), history of hypertension (OR = 3.046[1.267–7.322], P = 0.013), and neutrophil–lymphocyte ratio (NLR) ≥2 (OR = 3.261[1.020–10.419], P = 0.046) were independent risk factors for major POCD. Receiver operating characteristic curve analysis indicated that VAS score (1st day, resting) was a significant predictor for major POCD with a cut-off value of 2.68 and an area under the curve of 0.860 (95% confidence interval: 0.801–0.920, P < 0.001).ConclusionsThe risk factors for early POCD after gastroenterectomy included high VAS score (1st day, resting) and alcohol exposure. High VAS score, preoperative WBC levels ≥10 × 10*9/L, blood loss ≥500 ml, NLR ≥2, and history of hypertension were independent risk factors for major POCD. Among them, VAS score was one of the important predictors.

Assessment of risk factors for postoperative cognitive dysfunction after coronary artery bypass surgery: a single-center retrospective cohort study.

Aim: To find out risk factors for postoperative cognitive dysfunction (POCD) after coronary artery bypass grafting (CABG), and to provide basis for clinical prevention of POCD. A total of 88 patients who underwent CABG were surveyed with Telephone Questionnaire (TICS-M) for their cognitive impairment after 3, 7, 21, 90, 180 days post-surgery. The occurrence of POCD was diagnosed by Neuropsychological Battery which included Vocabular Learning Test (VLT), Wisconsin Card Sorting Test (WCST), Trail Making Test (TMT) and Symbol Digit Modalities Test (SDMT). The preoperative, intraoperative and postoperative risk factors were assessed by the χ2 or t test. Multivariate analysis was used to study the correlation between the risk factors and the occurrence of POCD. Age, aortic plaque, carotid artery stenosis, cerebrovascular disease, anesthesia time, the rate of decline in intraoperative hemoglobin concentration (ΔHb) and systemic inflammatory response syndrome (SIRS) score on postoperative day 2 had statistically significant (P<0.05) influence on the occurrence of POCD. Aortic plaque, carotid artery stenosis, anesthesia time and SIRS score (odds ratio (OR) value > 1, P<0.05) are the risk factors for POCD. The incidence of day-21 and -180 POCD was approximately 26.1 and 22.7%, respectively.

The value of intraoperative monitoring of cerebral oxygen saturation on postoperative cognitive function in elderly patients undergoing cardiac surgery

Objective: To investigate the effect of cerebral oxygen saturation (rSO2) on postoperative cognitive dysfunction (POCD) in elderly patients undergoing cardiac anesthesia. Methods: Retrospective analysis was performed on 113 elderly patients (age 65-89) underwent cardiac surgery in Peking University International Hospital from June 2017 to December 2019, 67 male and 46 female patients were included. All operations were performed under general anesthesia, cardiopulmonary bypass, rSO2 and other relevant monitoring. Statistical analysis of the elderly patients with complications, cardiac surgery history, time of CPB, baseline value of rSO2 (rSO2 baseline), lowest intraoperative value of rSO2 (rSO2 min), time of operation, length of stay in CCU, length of hospital stay; Preoperative and postoperative NSE values; number of postoperative POCD and postoperative deaths were recorded. All data were obtained from the medical records system and anesthesia information system of Peking University International Hospital and risk factors related to POCD were analyzed by Logistic regression. Results: POCD occurred in 19 patients (16.8%), and also, intraoperative rSO2 decreased by more than 30% over the baseline. The variance of rSO2 (rSO2 baseline-rSO2 min) in POCD group and non-POCD group was (18.0±2.7) and (6.6±2.3), the variance of NSE (NSE after surgery-NSE before surgery) was (31.3±9.7) and (9.5±3.0) μg/L, respectively. The differences were statistically significant (t=18.35, 17.70, all P<0.05). rSO2 variability was positively correlated with NSE variability (r=0.697, P<0.05). Logistic regression analysis showed that the variation degree of rSO2 [OR(95%CI)was 0.374(0.059-1.895)]、 patients combined with diabetes mellitus [OR(95%CI)was 0.493 (0.041-1.812), history of stroke [OR(95%CI)was 0.325 (0.084-0.917)] and atrial fibrillation [OR(95%CI)was 0.176 (0.091-0.943)] were the risk factors for POCD. Conclusion: POCD can be predicted by monitoring the decline range of rSO2 intraoperatively. rSO2 is recommended as a routine monitoring item for elderly patients undergoing cardiac surgery.

Postoperative cognitive dysfunction in elderly patients undergoing hip arthroplasty.

Even after successful hip arthroplasty, elderly patients who have undergone this procedure remain subject to cognitive decline and may collectively develop postoperative cognitive dysfunction (POCD). However, no consensus exists as to the risk factors resulting in a higher likelihood that a patient may present with this complication, and the aetiology of POCD is not well understood. We conducted a systematic review of papers concerning the influence of POCD-related risk factors in patients undergoing hip arthroplasty but limited the literature search to papers in English. A systematic and electronic search for manuscripts in the PubMed database was performed in order to identify all studies in which the risk factors for POCD were investigated. Articles were also obtained from the authors' files. Keywords for the search were postoperative cognitive dysfunction/change/impairment/decline/deficit, elderly/older/aged patients, and hip arthroplasty/replacement surgery. The evidence published to date suggests that POCD is a multifactorial disease, which includes an individual patient's characteristics, surgery, type of anaesthesia, and pain levels. All of these factors can increase the risk of POCD incidence. There are a number of factors that appear to influence the risk of early cognitive dysfunction after hip arthroplasty. Nevertheless, the specific mechanism and explicit risk factors associated with this cognitive dysfunction are not completely understood. Hip arthroplasty has made it possible for older patients to find relief from pain and improve their function, whereas it also increases the risk for suffering POCD that may affect these patients' quality of life and increase their mortality. Therefore, it is worthwhile investigating the mechanism of POCD in future studies in order to prevent and treat this condition.

A Novel Individual-based Determination of Postoperative Cognitive Dysfunction in Mice.

Postoperative cognitive dysfunction (POCD) is a significant clinical issue. Aging is a risk factor for POCD. It is known that not every patient develops POCD. This situation shall be similar in animals. Determination of POCD is individual-based in humans but group-based in animal studies. This difference prevents effective evaluation of biomarkers and interventions for POCD in preclinical studies. The objective of this study was to determine whether individual animal could be assessed for POCD by a system similar to that for patients. Seven-week old CD1 and 18-month old C57BL/6 male mice were subjected to right carotid arterial exposure under isoflurane anesthesia. Mice were evaluated by Barnes maze and fear conditioning either post-surgery alone or both prior to surgery and post-surgery. Surgery increased the time to identify the target box in Barnes maze when tested one day or 8 days after the training sessions and reduced freezing behavior in fear conditioning test. This phenomenon occurred in 7-week old animals with and without evaluation before the surgery and in 18-month old mice evaluated before and after surgery. Based on the method and criteria used for a human whose cognition was evaluated before and after surgery to assess individual decline of cognition, 7 in 21 mice in the surgical group and 1 in 21 mice in control group of 7-week old mice had cognitive dysfunction. Among 18-month old mice, 13 in 21 mice in the surgical group and 2 in 20 mice in the control group had cognitive dysfunction. The incidence of cognitive dysfunction in mice with surgery was higher than that in control mice no matter whether young adult (P = 0.045) or old mice (P < 0.001) were considered. These results indicate that surgery induces POCD in mice. Individual animal-based assessment can be used to identify animals with POCD.

Postoperative cognitive dysfunction after robot-assisted radical cystectomy (RARC) with cerebral oxygen monitoring an observational prospective cohort pilot study

BackgroundThe incidence and risk factors of postoperative cognitive dysfunction (POCD) during robot-assisted radical cystectomy (RARC) in extreme Trendelenburg positioning and pneumoperitoneum are still controversial. The aim of this prospective observational study was to find the incidence rate as well as possible risk factors of POCD in RARC with cerebral oxygen monitoring.MethodsPatients who underwent RARC and open abdominal surgery in horizontal positioning were included. Preoperative and postoperative arterial blood gas (ABG), S-100β, C-reactive protein (CRP), and cognitive dysfunction scales were tested. Also, we used Z score to analyze and comprehensively evaluate POCD. Measurements of heart rate (HR), mean arterial pressure (MAP), central venous pressure (CVP), end-tidal CO2 (etCO2), and cerebral oxygen were immediately obtained after different time points during the surgery.ResultsHere, 24 and 23 patients were included in the RARC group and in the control group, respectively. The incidence of POCD didn’t have significant difference in RARC group (45.8%), in contrast to the control group (26.1%). The laboratory tests of s100β and CRP between two groups didn’t contain significant difference as well. As duration of Trendelenburg and pneumoperitoneum prolonged, the cerebral oxygen saturation in the RARC group increased, which didn’t cause excessive perfusion nevertheless (rSO2<75%). We compared laboratory tests, age, education status, blood loss, and fluid input between POCD and non-POCD patients. A significant difference was found in the serum concentrations of CRP (72.59 ± 42.09 vs. 48.50 ± 26.53, P = 0.025) and age (69.20 ± 7.033 vs. 65.34 ± 5.228, P = 0.041).ConclusionRARC in extreme Trendelenburg positioning and pneumoperitoneum did not significantly increase the incidence of POCD and didn’t cause excessive perfusion. The inflammation marker CRP and age might be independent risk factors of POCD.Trial registrationClinicaltrials.gov with registration number NCT03372135. Registered 1 November 2017 (retrospectively registered).

Risk factors and a prognostic model for postoperative cognitive dysfunction after gynecologic laparoscopic surgery in elderly women

Objective To investigate the risk factors for postoperative cognitive dysfunction(POCD)after gynecologic laparoscopic surgery in elderly female patients, and to establish a risk model for prognosis. Methods Mini-Mental State Examination(MMSE)was used to evaluate the cognitive function of 280 elderly women who underwent gynecologic laparoscopic surgery from April 2014 to March 2016 in four tertiary-level hospitals in Hubei Province.Thirty-two cases were excluded due to withdrawal or loss of follow-up, and 248 cases with complete and valid data were collected for analysis.According to the degree of cognitive impairment on the 7th day after operation, subjects were grouped into a POCD group and a non-POCD group.Logistic regression was used to determine risk factors and establish a prognostic model for POCD. Results Of the 248 subjects enrolled, 62(25.0%)were diagnosed with POCD on the 7th day after operation.Multivariate Logistic regression analysis showed that American Society of Anesthesiologists(ASA)grade(OR=4.578, 95%CI: 1.156~18.139, P=0.030), age(OR=1.465, 95%CI: 1.230~1.745, P=0.000), and duration of anesthesia(OR=1.030, 95%CI: 1.005~1.056, P=0.017)were independent risk factors for POCD, and intraoperative administration of dexmedetomidine(OR=0.069, 95%CI: 0.508~14.094, P=0.011), dexamethasone(OR=0.135, 95%CI: 0.200~0.928, P=0.042), and maintenance of deep anesthesia(OR=0.761, 95%CI: 0.630 to 0.919, P=0.005)were protective factors.A prognostic model was established based on the principle of logistic regression equation.The receiver operating characteristic(ROC)curve determined Y=4.291 as the best risk value, and the expected sensitivity and specificity were 90.3% and 97.8%, respectively.Additionally, another 50 independent cases were included to verify the predictive efficacy of the model.It showed that the overall correct rate was 86.0%, and the sensitivity and specificity were 81.8% and 87.2%, respectively. Conclusions Increased ASA grade, advanced age, prolonged anesthesia time are independent risk factors for POCD, and intraoperative administration of dexmedetomidine, dexamethasone, maintenance of deep anesthesia play a protective role.The prognosis model of POCD has certain clinical value. Key words: Cognitive disorders; Anesthesia, general; Risk factor

Risk factors for early postoperative cognitive dysfunction after colorectal surgery

BackgroundIt has been reported that postoperative cognitive dysfunction (POCD) is correlated with the degeneration of the central nervous system, oxidative stress, inflammation, and endocrine and immune dysfunction. Increased age, predisposed comorbidity, long surgery time, and prolonged stay in the intensive care unit have been reported to be risk factors for developing POCD for cardiac surgery. In the present study, the risk factors of early POCD after colorectal surgery were investigated.MethodsEighty patients, who provided informed consents for their participation in this study, were enrolled and received colorectal surgery under general anesthesia. Neuropsychological tests were performed preoperatively and on postoperative day seven. The risk factors for POCD were analyzed using a multivariate logistic regression model.ResultsNineteen patients were diagnosed with POCD (24.7%). Diabetes history (OR = 8.391 [2.208–31.882], P = 0.012), fasting over 3 days after surgery (OR = 5.236 [1.998–13.721], P = 0.001) and an SIRS score of > 3 on the second day after surgery (OR = 6.995 [1.948–25.111], P = 0.003) were risk factors for early POCD in colorectal cancer patients.ConclusionThe risk factors for early POCD after colorectal surgery included diabetes history, fasting over 3 days, and an SIRS score of > 3 on the second day.

Intranasal Insulin Prevents Anesthesia-induced Cognitive Impairments in Aged Mice.

Preclinical and clinical evidence suggests that elderly individuals are at increased risk of cognitive decline after general anesthesia. General anesthesia is also believed to be a risk factor for Postoperative Cognitive Dysfunction (POCD) and Alzheimer's Disease (AD). Intranasal administration of insulin, which delivers the drug directly into the brain, improves memory and cognition in both animal studies and small clinical trials. However, how insulin treatment improves cognitive function is poorly understood. Aged mice were pretreated with intranasal insulin or saline before anesthesia. Propofol was added intraperitoneally to the mice from 7th day of insulin/saline treatment, and general anesthesia was induced and maintained for 2 hours/day for 5 consecutive days. Mice were evaluated at 26th day when the mice were continued on insulin or saline administration for another 15 days. We found that intranasal insulin treatment prevented anesthesia-induced cognitive impairments, as measured by novel object recognition test and contextual-dependent fear conditioning test. Insulin treatment also increased the expression level of Post-synaptic Density Protein 95 (PSD95), as well as upregulated Microtubule-associated Protein-2 (MAP-2) in the dentate gyrus of the hippocampus. Furthermore, we found that insulin treatment restored insulin signaling disturbed by anesthesia via activating PI3K/PDK1/AKT pathway, and attenuated anesthesia-induced hyperphosphorylation of tau at multiple AD-associated sites. We found the attenuation of tau hyperphosphorylation occurred by increasing the level of GSK3β phosphorylated at Ser9, which leads to inactivation of GSK-3β. Intranasal insulin administration might be a promising therapy to prevent anesthesiainduced cognitive deficit in elderly individuals.

Effect of emodilutional anemia on postoperative cognitive function in patients undergoing cardiopulmonary bypass

Objective To evaluate the effects of hemoglobin(Hb) concentrations during cardiopulmonary bypass (CPB) on postoperative cognitive dysfunction (POCD) in patients. Methods One hundred and eight patients underwent cardiopulmonary bypass were enrolled in this study. According to their Hb concentrations, patients were divided into 3 groups. Patients with normal levels of Hb, 90-110, 60-90 g/L Hb were respectively assigned into groupⅠ, group Ⅱ and group Ⅲ. The patients′ Hb concentration 1 day before the surgery, during cardiopulmonary bypass, 1, 2, 3, 4 and 7 days after the surgery were measured. The cerebral oxygen saturation (rSO2) was also assayed during CPB. The score of the neuropsychological test on the day before surgery and the seventh day after surgery were recorded. Whether Hb concentration and rSO2 levels affect the incidence of postoperative cognitive function was analyzed. Results Among three groups, no significant difference was found in basic and operative information, and the score of the neuropsychological test on one day before surgery(P>0.05). The neuropsychological scores at the seventh day after surgery were lower in group Ⅲ compared with group Ⅰ(P<0.05). The incidence of POCD was higher in group Ⅱ and group Ⅲ than that in group Ⅰ (P<0.05). Compared with group Ⅰ, the rSO2 mean and rSO2 min were lower in group Ⅱ and Ⅲ on the seventh day after surgery(P<0.05). Conclusions Patients with anemia are susceptible to POCD, which might be related to decreased cerebral oxygen saturation. Hb concentration may be an independent risk factor for POCD. Key words: Cerebral oxygen saturation; Hemoglobin; Anemia; Postoperative cognitive dysfunction

Diabetes, but Not Hypertension and Obesity, Is Associated with Postoperative Cognitive Dysfunction

Background/Aims: Older people undergoing surgery are at risk of developing postoperative cognitive dysfunction (POCD), but little is known of risk factors predisposing patients to POCD. Our objective was to estimate the risk of POCD associated with exposure to preoperative diabetes, hypertension, and obesity. Methods: Original data from 3 randomised controlled trials (OCTOPUS, DECS, SuDoCo) were obtained for secondary analysis on diabetes, hypertension, baseline blood pressure, obesity (BMI ≥30 kg/m²), and BMI as risk factors for POCD in multiple logistic regression models. Risk estimates were pooled across the 3 studies. Results: Analyses totalled 1,034 patients. POCD occurred in 5.2% of patients in DECS, in 9.4% in SuDoCo, and in 32.1% of patients in OCTOPUS. After adjustment for age, sex, surgery type, randomisation, obesity, and hypertension, diabetes was associated with a 1.84-fold increased risk of POCD (OR 1.84; 95% CI 1.14, 2.97; p = 0.01). Obesity, BMI, hypertension, and baseline blood pressure were each not associated with POCD in fully adjusted models (all p > 0.05). Conclusion: Diabetes, but not obesity or hypertension, is associated with increased POCD risk. Consideration of diabetes status may be helpful for risk assessment of surgical patients.

Postoperative Cognitive Dysfunction Induced by Different Surgical Methods and Its Risk Factors

The aim of the present study was to compare the effect of different surgical methods on postoperative cognitive function in patients undergoing abdominal surgery, determine the risk factors of postoperative cognitive dysfunction (POCD) by logistic regression, and investigate these risk factors through different surgical methods. A total of 70 patients undergoing selective abdominal surgery were selected into this study. The age of these patients ranged within 32 to 85 years. The cognitive function of these patients was assessed by the mini-mental state examination at one day before the operation, and at the first and seventh day after the operation. The temperature of the tympanic membrane, PETCO₂ values, visual analogue scale scores, educational level, and operation time were recorded. Logistic regression analysis was used to analyze related factors of POCD. The incidence rate of perioperative hypothermia in groups O and L were 31.2 and 10.5 per cent, respectively; and the difference was statistically significant (P < 0.05). The difference in visual analogue scale scores at the first and seventh day after the operation between these two groups were statistically significant (P < 0.01). The incidence of POCD in group O was significantly higher than that in group L at the first and seventh day after the operation (P < 0.05). According to logistic regression results, it was found that age, perioperative hypothermia, and postoperative pain were risk factors of POCD. The difference in POCD for the patients undergoing abdominal surgery through different surgical methods was statistically significant, and this was closely correlated to perioperative hypothermia and postoperative pain.

Postoperative cognitive dysfunction after cochlear implantation

Postoperative cognitive dysfunction (PCD) is a subtle, prolonged deterioration in cognition after surgery. This complication has been frequently investigated, mainly after major (cardiac) surgery. However, the incidence after cochlear implantation is unknown. Therefore, the aim of the study was to investigate the incidence and possible risk factors of PCD in severely hearing-impaired older adults after cochlear implantation. In a prospective cohort study, 26 older participants (age: M = 70, SD = 8years), scheduled for cochlear implantation, were assessed prior to and 1week after implantation by means of the Montreal Cognitive Assessment (MoCA). The incidence of PCD was calculated. In addition, the following possible risk factors were recorded: age, sex, education, duration of hearing impairment, preoperative signs of depression and anxiety, duration of anesthesia, anesthetic and surgical events and postoperative complications. The incidence of PCD was 11.5%, defined by a Z score of change in MoCA scores ≥1.96 (i.e., a decrease of ≥4 points). The incidence of PCD was corrected for practice effects by incorporating data from a reference group. Besides an effect of age on the postoperative cognitive performance, no significant risk factors were identified. The incidence of PCD after cochlear implantation is lower than after major surgeries, but higher than after other minor surgeries. Routine cognitive screening before and after cochlear implantation is recommended to identify patients with PCD and to provide additional care for these patients.